The euro, which lost sharply after his comments sparked outflows from stocks and other risk assets, held steady at lower levels ahead of Europe's bank stress test results on Friday.
Bernanke, in testimony prepared for delivery to the Senate Banking Committee, said the U.S. economy faces unusually uncertain prospects.
Although he said the Fed was ready to take further steps to bolster growth if needed, analysts said lack of clarity on what measures it could take prompted investors to reduce risk positions, benefiting the low-yielding yen across the board.
The dollar fell 0.4 percent in Asian trade to 86.65 yen JPY=, extending losses after a 0.5 percentage point fall on Wednesday, on a mixture of offers from Japanese exporters and hedging selling related to some currency-linked structured notes.
Some market players say the dollar could fall below a seven-month trough of 86.27 yen hit last week.
Some say there will be a lot of stop-losses below the current levels. I think the dollar could fall fast if it breaks below 86 yen, said a trader at a European bank.
Option traders have said the market has short gamma positions below 85 yen, which means there will likely be more hedge-selling if the currency falls below that level.
A relentless drop in U.S. bond yields is also reducing the allure of the dollar in comparison with the yen.
The two-year U.S. Treasury note yield fell to a record low around 0.56 percent, following Bernanke's comments, shrinking the yield spread of two-year U.S bonds over Japanese government debt to a fresh 15-month low.
Others were less convinced about the likelihood of further falls in the dollar.
The pair's 14-day relative strength index is at 33, near the 30 mark considered to indicate an oversold market.
Yuki Sakasai, FX strategist at Barclays Capital, said the dollar/yen was unlikely to fall below the low for now.
What Bernanke has said is essentially the same as the minutes (of the Fed's June 22-23 meeting). So his comments alone are unlikely to push the dollar/yen below recent trading ranges, Sakasai said.
The rise in the yen, which gained steeply on the crosses on Wednesday, has been hampered by caution that Japanese policy makers may try to talk it down as it nears a 14-year high around 85 yen per dollar hit last November.
Deputy Finance Minister Motohisa Ikeda on Thursday said Japan wants to avoid excessive rises in the yen but market reaction was muted.
The euro ticked up to $1.2768 EUR=, winning some reprieve after having lost nearly a full percent in the previous session on Bernanke's comments as well as tepid demand at a Portuguese debt sale.
It has some support at its 14-day moving average around $1.2742 and around $1.2720, a July 9 high that will now be support.
The currency is likely to consolidate around the current levels, as few traders will be eager to push it higher before the European Union unveils the stress tests on euro zone banks.
The euro has had a good run against the dollar in recent weeks, rising to a 10-week high above $1.30 on Tuesday as traders began to bet most of the 91 European banks being examined would pass the tests.
European policy makers have expressed confidence their banks would pass, although some analysts say investors remain sceptical about the severity of the health checks.
Major listed banks, which face constant investor scrutiny, are expected to pass, but the tests may show the worst problems lie with smaller players such as Spanish cajas and German landesbanks, which are mainly unlisted. (Editing by Joseph Radford)